Hi again, I was reminded that the "history of Chelmsford" is available at Google / Books. And I did a search for GILSON and found 3 pages mentioning the name. One page lists the first settlers in Chelmsford in 1658, and Joseph GILSON is mentioned. Another page mentions a Solomon GILSON in 1776 and 1777. Another page mentions a Robert GILSON in 1760. I checked GILLSON, and there is a reference to a John GILLSON and a Jonathan GILLSON in 1760. That's all I'll offer, or ask, this morning. Betty (near Lowell, MA) P.S. Out of curiousity, I just searched for "Gilson's Hill, Billerica" and found it mentioned on this page: http://www.localhikes.com/Hikes/BillericaStateForest_1123.asp OH -- just discovered that the Billerica book is now at www.google.com Gilson's Hill is mentioned but not a reference to how it was named. There was a 2008 newspaper article about Warren MANNING, and "Manning State Park" in Billerica was created in his honor. And it says that he was responsible for keeping Gilson's Hill as "open space." (The "history of Chelmsford" is available at www.google.com and on CD.) (The "history of Billerica" is at HeritageQuest through your library (I believe). I do not know if it is available on CD, but it is available through the Billerica Historical Society.) (Both great resources. Towns were both incorporated in 1655 and many families in 1600's lived in both towns.)